The Day the Mesozoic Died 7 24 PDF

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The Day the Mesozoic Died Watch the video “The Day the Mesozoic Died” (https://www.biointeractive.org/classroomresources/day-mesozoic-died) and answer the following questions. (This worksheet is adapted from a student handout on Biointeractive.org.) 1. What is the K-T boundary? A thin layer of clay that separates rock layers from the end of the Cretaceous period to those from the beginning of the Tertiary period.

2. What are foraminifera? Describe the differences in the diversity and appearance of foraminifera above and below the K-T boundary. Rocks of the cretaceous were described as packed with foraminifera Below – foraminifera fossils were larger and more diverse Above – most foraminifera fossils disappeared; surviving species were smaller

3. Why did Walter Alvarez test for Iridium in the clay of the K-T boundary? Because Iridium is commonly found in meteors, so testing for Iridium would conclude the change in era had to possibly do with a meteor.

4. What is an alternative hypothesis for the high levels Iridium in the K-T boundary? Why was this hypothesis dismissed? A supernova explosion but was debunked because it was a 1 in a billion chance of a supernova happening that close to earth. A supernova explosion would release plutonium 244, but there wasn’t any in the sample.

5 Describe evidence that was used to determine that the asteroid hit on the Yucatan peninsula as opposed to elsewhere in the world. Much shock quartz was found in Penfield’s rock samples from the chicxulub crater showing high energy impact occurred.

6. Describe how life on the planet was different after the asteroid hit both during the first million years and then after the first million years.

Right after the impact, if not immediately killed, the fire and smoked blocked out the sun leaving anything dependent on photosynthesis to die, food chains collapse. 60% of all plant species went extinct. There was eventually a fern spike where the land grew many ferns. After the first million years, animals started coming back into the environment. The only creatures that may have survived would be animals that lived in holes, birds, rodents, turtles, frogs, swamp and river creatures, or things near the seashore (all were small animals). Beginning the age of mammals.

7. What do you think life on earth would be like now if the asteroid had not struck the earth? I believe there would still be dinosaurs, assuming no disasters occurred, there would never be mammals because they could not live beside dinosaurs.

8. The K-T event was only one of five major extinction events in the history of earth. Do some research and find out when the other four events occurred and what scientists think caused them. End Ordovician was 444 million years ago that took out 86% of species caused by an ice age chilling the planet. Late Devonian was 375 million years ago taking out 75% of species caused by changes in the land due to evolving plants and changes in the oceans. End Permian was 251 million years ago that took out 96% of species caused by a cataclysmic eruption near Siberia that released much CO2 into the atmosphere. End Triassic was 200 million that took out 80% of species and the cause was not found....